Synthesis Optimization of L-Aspartic acid β-hydroxamate by a novel Enzyme, β-Aspartyl-γ-glutamyl transferase

L-Aspartic acid β-hydroxamate or L-β-Aspartyl hydroxamate (BAH), water soluble- chemical compound currently obtains popularity due to its role in several important biochemical processes and to its bioactivities. The information regarding synthesis process of BAH is not available yet. Novel enzyme, β-aspartyl-γ-glutamyl transferase from Pseudomonas syringae can catalyze the transfer reaction of β-aspartyl moieties from β-aspartyl compounds to water or to hydroxylamine. In this study we describe the synthesis optimization of BAH using this novel enzyme. We prepared the L-β-aspartyl hydroxamate using L- asparagine as a donor substrate and hydroxylammonium chloride as an acceptor substrate. The effects of temperature, pH, concentrations of substrate donor and acceptor were investigated. Spectrophotometry and HPLC analyses were performed to determine the reaction products. The optimum synthesis reaction was observed in 60˚C. BAH synthesis was optimum at pH 6. The concentrations of donor and acceptor substrates affected the BAH production and the best concentrations of both substrates were 80 mM and 40 mM, respectively. The BAH production of 0.106 mM has been obtained under the optimized condition and it is approximately two-times higher than 0.047 mM produced under in standard reaction. In conclusion, biosynthesis of L-β-aspartyl hydroxamate using a novel enzyme, β- aspartyl-γ-glutamyl transferase from Pseudomonas syringae was successfully performed for the first time. Under the optimized conditions, two times higher L-β-aspartyl hydroxamate production was obtained

The evidence and the rationale for the use of honey as wound dressing

Although there are now several brands and types of honey wound-care products available as registered medical devices, there is little promotional advertising of honey products for wound care. The misconception that there is no evidence to support the use of honey, which seems to be quite common, may be due to this lack of advertising, and to the systematic reviews that have been published on honey concluding that the evidence is of low quality and/or there is a need for more evidence. However, the same lack of high-quality evidence exists with all the other options that clinicians have for dressing wounds. This places practitioners in a quandary. When clinical evidence of the highest level is not available, then decisions on modes of treatment need to be based on whatever evidence there is available. This review outlines the 16 randomised controlled trials (RCTs) of honey in wound care published since Molan reviewed the previous 17 in 2006, which bring the total of participants in the trials up from 1,965 to 3,556 and broadens the range of types of wounds on which trials with honey have been conducted. Another important factor influencing the choice by clinicians of which product to use on a wound is scientific rationale. This review covers the evidence and explanation of mode of action for various bioactivities in honey which aid wound healing: a very broad-spectrum antimicrobial activity that is effective on antibiotic-resistant strains; activation of autolytic debridement; anti-inflammatory activity; antioxidant activity; stimulation of growth of cells for tissue repair; and an osmotic action. The need for standardisation of these bioactivities is discussed

Alkylresorcinols in cereal grains

Alkylresorcinols are phenolic lipids present at levels of up to 0.15% of whole grain wheat and rye, but little is known about their presence in food, absorption in animals and humans, and their in vivo biological effects. Because alkylresorcinols are present in the human diet in significant amounts only in products containing whole grain wheat or rye, they have potential to be biomarkers of whole grain wheat and rye intake. This thesis describes some of the research undertaken to investigate whether alkylresorcinols could be biomarkers of whole grain wheat and rye intake. A rapid gas chromatographic method was developed to analyse alkylresorcinols in whole cereal grains. This method was then applied to detect the presence and amount of alkylresorcinols in several cereal grains. Wheat, rye and triticale all contain moderate to high amounts of alkylresorcinols (300-1500 µg/g), while barley contains low amounts (~50 µg/g). In these cereals, alkylresorcinols are present in the bran fraction. All other cereals analysed (rice, oats, maize, sorghum and millet) did not contain any detectable amounts of alkylresorcinols. Previous studies have suggested that alkylresorcinols are destroyed by the baking process. However, an extraction method using hot propanol:water was able to recover all alkylresorcinols from experimental breads, indicating that alkylresorcinols are not destroyed during baking. The absorption of alkylresorcinols in rats, pigs and humans was determined, with values for absorption ranging from 34–79%, depending on the model and the amount of alkylresorcinols consumed. Alkylresorcinols in the plasma of pigs fed a single meal of rye, peaked at 3-4 hours, and remained elevated compared to the baseline levels after 16 hours. Preliminary studies to find alkylresorcinol metabolites in humans suggest that they have their alkyl chains shortened by β-oxidation. The effect of purified rye alkylresorcinols on lipid parameters (tocopherols, cholesterol and fatty acids) was tested on a rat model. Alkylresorcinols did not appear to affect rat performance, but in high amounts they could decrease liver cholesterol, and moderately elevate γ-tocopherol levels. Overall, the results suggest that alkylresorcinols do not have a large effect on lipid absorption/metabolism in rats

A multilayer network approach for guiding drug repositioning in neglected diseases

Drug development for neglected diseases has been historically hampered due to lack of market incentives. The advent of public domain resources containing chemical information from high throughput screenings is changing the landscape of drug discovery for these diseases. In this work we took advantage of data from extensively studied organisms like human, mouse, E. coli and yeast, among others, to develop a novel integrative network model to prioritize and identify candidate drug targets in neglected pathogen proteomes, and bioactive drug-like molecules. We modeled genomic (proteins) and chemical (bioactive compounds) data as a multilayer weighted network graph that takes advantage of bioactivity data across 221 species, chemical similarities between 1.7 105 compounds and several functional relations among 1.67 105 proteins. These relations comprised orthology, sharing of protein domains, and shared participation in defined biochemical pathways. We showcase the application of this network graph to the problem of prioritization of new candidate targets, based on the information available in the graph for known compound-target associations. We validated this strategy by performing a cross validation procedure for known mouse and Trypanosoma cruzi targets and showed that our approach outperforms classic alignment-based approaches. Moreover, our model provides additional flexibility as two different network definitions could be considered, finding in both cases qualitatively different but sensible candidate targets. We also showcase the application of the network to suggest targets for orphan compounds that are active against Plasmodium falciparum in high-throughput screens. In this case our approach provided a reduced prioritization list of target proteins for the query molecules and showed the ability to propose new testable hypotheses for each compound. Moreover, we found that some predictions highlighted by our network model were supported by independent experimental validations as found post-facto in the literature.Fil: Berenstein, Ariel José. Fundación Instituto Leloir; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física; ArgentinaFil: Magariños, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Chernomoretz, Ariel. Fundación Instituto Leloir; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física; ArgentinaFil: Fernandez Aguero, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

Alkaloids from the Sponge Stylissa carteri Present Prospective Scaffolds for the Inhibition of Human Immunodeficiency Virus 1 (HIV-1).

The sponge Stylissa carteri is known to produce a number of secondary metabolites displaying anti-fouling, anti-inflammatory, and anti-cancer activity. However, the anti-viral potential of metabolites produced by S. carteri has not been extensively explored. In this study, an S. carteri extract was HPLC fractionated and a cell based assay was used to evaluate the effects of HPLC fractions on parameters of Human Immunodeficiency Virus (HIV-1) infection and cell viability. Candidate HIV-1 inhibitory fractions were then analyzed for the presence of potential HIV-1 inhibitory compounds by mass spectrometry, leading to the identification of three previously characterized compounds, i.e., debromohymenialdisine (DBH), hymenialdisine (HD), and oroidin. Commercially available purified versions of these molecules were re-tested to assess their antiviral potential in greater detail. Specifically, DBH and HD exhibit a 30%-40% inhibition of HIV-1 at 3.1 μM and 13 μM, respectively; however, both exhibited cytotoxicity. Conversely, oroidin displayed a 50% inhibition of viral replication at 50 μM with no associated toxicity. Additional experimentation using a biochemical assay revealed that oroidin inhibited the activity of the HIV-1 Reverse Transcriptase up to 90% at 25 μM. Taken together, the chemical search space was narrowed and previously isolated compounds with an unexplored anti-viral potential were found. Our results support exploration of marine natural products for anti-viral drug discovery

Microbial communities and bioactive compounds in marine sponges of the family Irciniidae-a review

Marine sponges harbour complex microbial communities of ecological and biotechnological importance. Here, we propose the application of the widespread sponge family Irciniidae as an appropriate model in microbiology and biochemistry research. Half a gram of one Irciniidae specimen hosts hundreds of bacterial species-the vast majority of which are difficult to cultivate-and dozens of fungal and archaeal species. The structure of these symbiont assemblages is shaped by the sponge host and is highly stable over space and time. Two types of quorum-sensing molecules have been detected in these animals, hinting at microbe-microbe and host-microbe signalling being important processes governing the dynamics of the Irciniidae holobiont. Irciniids are vulnerable to disease outbreaks, and concerns have emerged about their conservation in a changing climate. They are nevertheless amenable to mariculture and laboratory maintenance, being attractive targets for metabolite harvesting and experimental biology endeavours. Several bioactive terpenoids and polyketides have been retrieved from Irciniidae sponges, but the actual producer (host or symbiont) of these compounds has rarely been clarified. To tackle this, and further pertinent questions concerning the functioning, resilience and physiology of these organisms, truly multi-layered approaches integrating cutting-edge microbiology, biochemistry, genetics and zoology research are needed.Portuguese Foundation [PTDC/MAR/101431/2008, PTDC/BIA-MIC/3865/2012]; European Regional Development Fund (ERDF) through the Operational Competitiveness Programme (COMPETE); national funds through FCT (Foundation for Science and Technology) [PEst-C/MAR/LA0015/2011]; FCT [SFRH/BD/60873/2009]info:eu-repo/semantics/publishedVersio

Review

The chalcogen elements oxygen, sulfur, and selenium are essential constituents of side chain functions of natural amino acids. Conversely, no structural and biological function has been discovered so far for the heavier and more metallic tellurium element. In the methionine series, only the sulfur-containing methionine is a proteinogenic amino acid, while selenomethionine and telluromethionine are natural amino acids that are incorporated into proteins most probably because of the tolerance of the methionyl-tRNA synthetase; so far, methoxinine the oxygen analogue has not been discovered in natural compounds. Similarly, the chalcogen analogues of tryptophan and phenylalanine in which the benzene ring has been replaced by the largely isosteric thiophene, selenophene, and more recently, even tellurophene are fully synthetic mimics that are incorporated with more or less efficiency into proteins via the related tryptophanyl- and phenylalanyl-tRNA synthetases, respectively. In the serine/cysteine series, also selenocysteine is a proteinogenic amino acid that is inserted into proteins by a special translation mechanism, while the tellurocysteine is again most probably incorporated into proteins by the tolerance of the cysteinyl-tRNA synthetase. For research purposes, all of these natural and synthetic chalcogen amino acids have been extensively applied in peptide and protein research to exploit their different physicochemical properties for modulating structural and functional properties in synthetic peptides and rDNA expressed proteins as discussed in the following review

Profiling of aminoxyTMT-labeled bovine milk oligosaccharides reveals substantial variation in oligosaccharide abundance between dairy cattle breeds.

Free milk oligosaccharides are bioactive molecules that function as prebiotics and prevent infections that commonly afflict developing infants. To date, few publications have examined the factors affecting bovine milk oligosaccharide production among cattle in the dairy industry. Here we have applied a high-throughput isobaric labeling technique to measure oligosaccharide abundances in milk collected from Danish Holstein-Friesian and Jersey dairy cattle by liquid chromatography-mass spectrometry. With a total of 634 milk samples, this collection represents the largest sample set used for milk oligosaccharide profiling in the current literature. This study is also the first to use isobaric labeling for the purpose of measuring free oligosaccharides in a real sample set. We have identified 13 oligosaccharides that vary significantly by breed, with most structures being more abundant in the milk of Jersey cattle. The abundances of several oligosaccharides were increased in second-parity cows, and correlations between the abundances of oligosaccharide pairs were identified, potentially indicating similarities in their synthetic pathways. Fucosylated oligosaccharide structures were widely identified among both breeds. Improving our understanding of oligosaccharide production will aid in developing strategies to recover these compounds from processing streams and may enable their use as a functional ingredient in foods for infants and adults